On the Thermal Attack in Instruction Caches

The instruction cache has been recognized as one of the least hot units in microprocessors, which leaves the instruction cache largely ignored in on-chip thermal management. Consequently, thermal sensors are not allocated near the instruction cache. However, malicious codes can exploit the deficiency in this empirical design and heat up fine-grain localized hotspots in the instruction cache, which might lead to physical damages. In this paper, we show how instruction caches can be thermally attacked by malicious codes and how simple techniques can be utilized to protect instruction caches from the thermal attack.